Two controversial world records were set on Wednesday over the course of a historic hour. Joshua Cheptegei broke the men’s 10,000m record, shaving six seconds off the previous time, while Letesenbet Gidey took four seconds off the women’s 5,000m time earlier at the event.
Both athletes made history while wearing Nike ZoomX Dragonfly spikes, a new version of the Nike Vaporfly shoe worn by a number of world record breaking athletes, including Mo Farah.
At the event in Valencia, which had been branded as “World Record Day” in advance, Cheptegei broke a world record that had been set in 2005 by Kenenisa Bekele. The 24-year-old now possesses both the 10,000m and 5,000m world record, having broken the latter earlier this year.
Gidey’s performance in the women’s 5000m was just as astounding, recording a time of 14min 6.62sec, breaking Tirunesh Dibaba’s 2008 record.
The event was organised by Cheptegei’s NN Running Team. Both world record breakers were assisted by pacers and Wavelight technology, which flashes lights on the track to indicate the specific pace required to beat the previous record.
Nike’s contentious spikes are made with a carbon plate and a specially designed foam. The design aims to limit the amount of energy lost each time the foot makes contact with the ground. A number of studies have been conducted by both Nike and independently to evaluate the shoe, with the results suggesting that performance can be improved by four per cent or more.
The frequency with which world records have been broken while wearing a version of these spikes have raised questions about their legitimacy. The shoes have revolutionised distance and marathon running, rendering world record after world record obsolete.
In January, new limits on footwear technology were announced that would be enforced from April. Nike’s controversial Vaporfly shoes were deemed legal however, despite the new measures. Although Nike’s prototype Alphafly shoes, which were worn by Eliud Kipchoge when he became the first man to run a marathon in under two hours, were deemed illegal for competition.